The objectives are to determine the following effects of exposure of an insect species to 4 consistent levels of a complex mixture of air pollutants: (1) the effects on growth rate, reproduction, survivorship, and life span over 12 successive generations; (2) the effects of air pollutants on animals exposed only at certain states of the life cycle; (3) possible synergistic actions of air pollutants and stress factors; and (4) the pathway or mechanism of action of the pollutants. Only two possible pathways will be investigated during the time of this study: effects on hormones controlling growth and development in insects and effects on metabolic rates. The pollutants will be SO2, NO, NO2, CH4, CO, and (NH4)2SO4. The levels of the gases in the mixture will be approximately those found in a typical urban environment, those found under high or episodic conditions, and those found under emergency conditions. The levels of pollutants are maintained by a programmed monitoring system with feedback control. These experiments will give us data which will allow predictions about certain effects of pollutants before those levels of pollutants actually have to be coped with.